Gantry crane



B. F. FITCH 2,063,913

GANTRY CRANE I Original Filed Jan. 24, 1954 Sheets-Sheet l 'Firq. 1

Fig. 2

Ema/whoa mww a B. F. FITCH GANTRY CRANE Dec. 15, 1936.

Original Filed Jan. 24, 1934 2 Sheets-$heet 2 Patented Dec. 15, 1936UNITED STATES earner creme GANTRY CRANE Original application January 24,1934, Serial No.

Divided and this application September 15, 1934, Serial No. 744,214

9 Claims.

This invention relates to a gantry adapted to carry an overheadtraveling crane, and is more particularly concerned with a movablegantry which may span a truck runway and, if desired, also a railroadtrack or a station platform, or both, enabling such gantry and itssupported crane to be effectively used to transfer demountable bodiesbetween a truck and a railroad car or station platform.

The present application is a division of my copending application No.708,125, filed January 24th, 1934, showing the gantry of this casesurmounted by a traveling crane arranged to engage a demountableautomobile body in the space beneath the gantry bridge.

, One of the objects of the present invention is to provide such gantryin the form which shall give a maximum clearance between the legs,thereby enabling the ready handling of demountable automobile bodieswithout requiring undue increase in the size of the gantry.

Another object of the invention is to so support the top of the gantrythat it is effectively fixed at its opposite ends, thus reducing thebending moment between the sides, enabling the top girders to be ofreduced depth and still support the same Weight of traveling crane.

Another object is to brace the top in a manner which shall be effectiveand at the same time allow cables to depend from the hoist at fourpoints corresponding to the four corners of a rectangle so that they maybe connected to a demountable automobile body and when so connected maytravel laterally to shift the body.

Still another object is to combine the gantry with a propellingmechanism protected by the gantry structure and acting on supportingwheels therefor, and thus adapted to cause the travel of the gantry as awhole.

My invention is illustrated in the drawings hereof and is hereinaftermore fully described.

In the drawings, Fig. 1 is an end elevation of my gantry; Fig. 2 is aplan thereof; Fig. 3 is a side elevation; Fig. 4 is a fragmentary sideelevation at one of the lower corners of the gantry, illustrating thepropelling mechanism; Fig. 5 is a detail of the propelling mechanism,being a vertical section indicated by the line 55 on Fig. 4.

As shown in Figs. 1, 2, and 3, my gantry comprises two side members Inand a top portion 20. The sides are composed of structural metal pieces,suitably bound together by angles and gusset plates. In general, arectangle is formed (best shown in Fig. 3), comprising a main bottomportion l I, an opposite parallel top portion l2, and Vertical legs l3.Internal braces for this rectangle are provided, as vertical members l5,horizontal members it and diagonal members ll, which project inwardlyfrom the centers of the top and bottom, and sides, and from the corners,all being joined by the gusset plate H3 at their point of intersection.Downwardly diverging outside braces is are provided in the verticalplane of the sides and meeting the legs H5 at the top and intersectingthe member H at the bottom of the gantry. Suitable plates M more firmlyfasten the members l9 and l3 together, and said members and plates formlongitudinal buttresses at each vertical edge of each gantry side.

The gantry is movable along a track composed of parallel rails 'ltl.Suitable flanged wheels ll, mounted at the corners of the sides, ride onthese rails and are driven by means mounted in a special manner on thegantry frame, as will hereinafter be more fully described.

The bridge at the top of the gantry is formed primarily of the twothrough girders 20 which extend transversely across the top of the legsl3 of the sides. They overhang these legs for some distance and arethere attached to structural members 36 which extend inwardly from theends of the girders to the outer faces of the legs adjacent their bottomwhere they are effectively secured to the legs, forming invertedbuttresses for the gantry frame. The inclined longitudinal braces l9overlap the sides of the girders and are secured to them. Suitable angleclips 3! and 32 and rivets (not specifically shown) may fasten themembers Sil and B9 to the webs of the girders 20.

It results from the construction just described that the girders 2B arefixed at their ends instead of being in effect merely supported at thetop of the sides, and as a girder fixed at its ends is twice as strongand four times as Stiff as if it was merely supported at its ends, itfollows that with my con struction a much lighter girder may be employedand still carry the same crane load.

The gantry bridge composed, as stated, primarily of the girders 2!), isbraced by bars 22 at the top of the sides and lattice members 23, which,with the side-top l2 form vertical trusses. Transversely there is ahorizontal lattice truss. As shown in Fig. 2, this lattice constructionconsists of side bars 4% leading from one side to the other, cross barsM and diagonal bracing 42 with suitable gussets 43 at the junctions ofthe diagonal members.

On top of each girder 20 is a rail 25 adapted to support a suitabletraveling crane designated 5!] having wheels 51 tracking on the rails.Suitable wheel stops 26 are provided at each end of the rails.

The construction of the top of the gantry as described is designedparticularly with reference to a crane having cables depending at fourpoints corresponding to the four corners of a rectangle, two of whichcables depend through each or" the spaces between one of the girders 20and the corresponding brace bar All. Such a crane is shown at 59 inFigs. 1 and 3, and indicated by broken lines in Fig. 2. Mounted in thecrane frame directly over the space between one of the girders 20 andthe adjacent brace bar 40, is a pair of winding drums 53 from which twocables 54 depend. Two other cables 55 lead from the drums across sheaves56 directly above the open space. The other side of the gantry top andsuch cables then depend through such open space.

The four depending cables 54. and 55 are suitably attached either to thebody to be lifted or to a suitable cradle adapted to be attached to thebody. As shown in Figs. 1 and 3, the cables pass around sheaves 60 on acradle (H which has shackles 62 adapted to engage hooks 0: at the eavesof the demountable body A. The long, narrow open spaces in the gantrytop, heretofore described, allow the depending cables while supportingthe body to shift freely as the crane travels.

The gantry crane, as shown in Fig. 1, is considerably smaller than maybe employed. For instance, the height of the sides 18 may besufiiciently increased to allow one body A to be raised above anadjacent body and moved thereover to be deposited on the other side ofthe latter. Such a change does not afiect my invention. Further, the top20 may be sufficiently widened to provide more spacing between the sidesl0, making it possible to accommodate a variety of body supports beneaththe top of the gantry. These supports may include loading platforms orconveyances, such as trucks, railroad cars and even ships, as desired.

Means are provided to move the entire gantry crane along the tracks 10,on which it rides. The bottom member l of each side is preferablycomposed of two outwardly facing channel beams spaced apart and securedtogether at intervals by bridge plates. These beams are shown moreclearly in Figs. 4 and 5. On the underside of the bottom beams arejournals '12. These journals support shafts 13, which, in turn, carrythe flanged wheels I l engaging the track members lil. There are two ofthese wheels at each of the four corners of the gantry frame, fourwheels to each rail.

The two pairs of wheels adjacent the same end of the two side frames areadapted to be driven, one pair on each rail. Mounted on a support 80,secured to the top flanges of the channel beams l l, is an electricmotor 8i. This motor is connected to worm reduction gearing 82, andthis, in turn, to an intermediate gear 83. Gears mounted on the wheels Hengage the gear 83. Thus, rotation of the motor 8i drives the gearedwheels H along the rail it, moving the gantry crane. Due to the drivebeing through a worm and its mating wormwheel, a self-locking brake isprovided as soon as the motor 8| is cut out of the circuit in which itis connected.

Mounted over each of the two driving mechanisms are protective hoods 9D.This hood may be of any shape, although I prefer to make it arcuate,with the ends 9! closed. When placed over the mechanism, this hood restson the members i i and is seciu'ely locked thereto by wing nuts 93,which clamp angles 94 to underfaces of the top flanges of the channelbeams.

It will be seen from the description given that I have provided aneffective out-of-door gantry adapted to span supports for differentvehicles and carry a suitable crane which may be effective to transfer abody from one vehicle to another or to a platform, if the same isemployed beneath the gantry. The specially formed buttresses providestiffness at each side, both against longitudinal and lateraldisplacement, while allowing a clear rectangular space between thegantry legs. Furthermore, the inverted buttresses at the sides of thegantry give double anchorage to the transverse girders so that they arein effect flxed at their ends instead of being merely supported, andthus the bending moment of such girders is greatly reduced. Thepropelling mechanism for the gantry is out of the way, being housedbetween the main legs and the longitudinally inclined braces, so that itdoes not use up valuable space on either side of the legs and isfurthermore protected by the structural members of the sides.

I claim:

1. A gantry having an overhead bridge, side members supporting it, saidside members having inverted buttresses extending laterally, there beingthrough girders at the top of the gantry extending across the legsthereof and connected with the upper portions of the invertedbuttresses, and lateral bracing connecting the top portions of the twosides and extending between the girders in spaced relation to both forsubstantially their entire length.

2. In a gantry having adjacent its lower end a pair of longitudinaloutwardly facing channel beams forming the base of the gantry, wheelshaving axles mounted on the channel beams, motor mechanism carried onsaid channel beams and drivingly associated with one of said wheels, thecombination therewith of a cover for the motor mechanism, bridging saidbeams, and clips engaging the cover and extending beneath the upperflanges of the two channel beams.

3. A gantry comprising overhead bridge girders adapted to support tracksfor a traveling crane on their top sides and vertical supporting memberssupporting the two end portions of the girders, outwardly overhung bythe extremities of the girders, said supporting members having invertedbuttress eifects including diagonally disposed straight structurallyflanged struts extending outwardly laterally from the bottom ends of thevertical members to the said extremities of the bridge girders, andbuttresses Wider at the bottom than at the top extending transversely ofthe bridge girders and from the top to the bottom of the gantry.

4. A gantry comprising an overhead bridge, side members supporting it,said side members each having two vertically upright legs withdiagonally outwardly extending straight flanged structural membersforming inverted buttress effects on the outer sides of said legs, andspaced through girders at the top of the gantry, connected rigidly withand extending across the legs and the upper ends of the invertedbuttress members in vertical alignment therewith, whereby said girdersare fixed at their ends against both upward and downward flexure.

5. A gantry having two rectangular side frames disposed vertically inparallel planes, said frames comprising horizontal base and top membersand vertical posts mutually interconnected by cross bracing, a top frameconnecting the side frames, said top frame including spaced girdersadapted to support traveling crane tracks, said girders extendingoutwardly beyond said side frames, straight diagonal flanged strutsdisposed outwardly beyond the side frames and connecting said girderextensions to the base members of the side frames to brace saidextensions vertically in two directions, the base members of said sideframes extending longitudinally beyond the posts, and structural membersforming triangular buttresses connecting said extended portions of thebase members with the upper ends of the vertical posts.

6. A gantry having a supporting bridge with parallel girders, adiagonally braced truss on said bridge between the girders and rigidlyconnected with both girders at its end portions in a manner to maintainthe girders in fixed relationship with each other, said truss beingcontinuously spaced from said girders laterally therefrom between thegirders to provide continual clearance adjacent the girders for cablesadapted to depend from a crane on the bridge.

7 Apparatus for handling demountable vehicle bodies, said apparatuscomprising horizontally spaced girders forming a supporting bridge, thegirders having tracks thereon, a crane movable on said tracks, fourcables depending from said crane in positions corresponding to the fourcorners of a rectangle for engagement with such demountable bodies, andlateral bracing on said bridge beneath said crane, said bracing beingcontinuously spaced from said girders for substantially the entirelength of said tracks to provide continual clearance for said dependingcables.

8. A gantry comprising an overhead bridge and supporting leg members atthe two sides thereof, said bridge having parallel crane-supportingmembers and having a diagonally braced truss structure connected withboth legs, disposed between the crane-supporting members in thehorizontal plane thereof and continuously spaced from saidcrane-supporting members for substantially the entire length of thetruss structure to provide clear narrow spaces in which cables adaptedto depend from a crane may travel.

9. A gantry having side members and an overhead bridge, each side memberincluding a pair of spaced horizontal base beams, a vertical supportingleg and a brace longitudinally beyond the leg flaring downwardly to thebase beams and providing a space between the vertical leg and the brace,wheels supported between the paired base beams and disposedsubstantially beneath the lower portions of said leg and brace, a motorlocated in the space between said leg and brace, and gearing between themotor and supporting wheels, said gearing being disposed at leastpartially between the spaced horizontal beams.

BENJAMIN F. FITCH.

